physics

(In memory of M.I.T. astrophysicist Dr. Philip Morrison - who started all this...)

Though the figures are tough to keep up with - they are changing, almost daily - the Kepler Space Telescope (KST) has discovered, to date, over 4,500 exoplanet candidates, ~3,400+ of which have been confirmed.

The term "sunspot" appears in the news, often in connection with stories on aurorae, electrical outages, and problems with orbiting satellites. But often these stories don't really explain what sunspots are and why they're of interest to us on Earth. So what are sunspots?